Lawn mower cutting mechanism



Dec. 30, 1941. A. RONNING 2,268,226

LAWN MOWER CUTTING MECHANISM Original Filed July 27, 1938 gjvwe/wbomADO-PH Pom/we Patented 1)...30, 1941 UNITED STATES 'PATENT OFFlCE2,2ss,22o

- Adolph Running, Minneapolis, Minn.

15, 1941. Divided and this 1940, Serial No. 338,008

application May 31,

4 Claims. (Cl. 56-249) My invention relates to improvements in cuttingmechanisms for lawn mowers.

The primary objectof the invention is to provide an improved ledger baror. fixed blade device for cooperation with the rotary cutter of a reeltype of mower and with means whereby the bar or knife may be reversedend to end in the mower to use either of two cutting edges with which itis provided. Another object is to provide improved supporting andmounting means for the bar or knife and by means of which it may beconveniently adjusted to proper cooperative cutting position withrespect to the rotary cutter.

These and .other more detailed and specific objects will be disclosed inthe course of the following specification, reference being had to theaccompanyingdrawing, in which Fig. l is a planview of a mower embodyingmy invention and with certain frame parts shown in section to betterillustrate theconstruction.

' Fig. 2 is an enlarged fragmentary vertical cross section through myledger bar or-knife assembly.

Fig. 3 is a vertical section along the line 3--3 Fig.4 is a verticalsection along the line 4-4 in Fig. 1. 7

It is here noted that this application is a division from my copendingapplication 'for United States patent on a Lawn mower, Serial No.221,538, filed July 27, 1938, now Patent No. 2,238,707, granted April15, 1941. Reference to this prior application is invited for a completedisclosure ofthe construction, operation, and advantages of the mowerper se, and the present disclosure will be limited to details essentialinFiK. 2..

. ends I of hangers or mounting members 8 which are turned upwardly tofit nicely between inner faces of the mower frame ends A. Bolts 9 arepassed through these hangers 8 and through the members A on transverseaxes just a short distance above the ledger bar and it will beevidentthat the entire assembly of ledger bar and its hangers may be rockedback and forth on .the

ypivot axes thus formed in order to bring the bar into proper cuttingrelationship to the cutter blades 0.

The bar is mounted on the frame members A .slightly to the rear of thevertical plane passing through the cutter shaft B (Fig. 4) and thereforeonly the forwardly disposed edge of the bar will be in cutting position.As this edge is dulled the bar may obviously be reversed end for end.

in the mower frame to present the other edge in cutting position, thuseffectively doubling the usual life of the ledger bar. The bolts 8 mayto the description of the subject of invention herein.

The mower comprises a. frame or housing including transversely spacedupright end plates or members A- through which is Journaled the cuttershaft B carrying the spiral cutter or reel blades C. The cutter is powerrotated by the power unit D and the mower is supported by the rearwardlyarranged ground roller E and a single forward ground wheel F. A handle,fragmentally shown at G, is used to manipulate and guide the mower.

The cutter blades C cooperate with the ledger bar, fixed knife, or blade5 which is arranged just clear of, or in shearing relation to, theblades as they travel their orbital path as will best be understood fromFig. 4. This bar 5 in accordance with my invention is formed or pressedfrom be reversed for this purpose by unscrewing their outwardly disposednuts ll).

Upwardly of the bolts 9 the hangers 8 are provided with upwardly andoutwardly opening re' cesses or grooves H in which are disposed cams 12carried eccentrlcally at the inner ends of studs l3 which are extendedoutwardly through the frame members A. The cams l2 are of such diameterthat they just nicely fit between the opposite front and rear uprightedges of the grooves II and by turning the cams it will obviously bepossible to urge' the upper ends of the hangers 8 either forwardly orrearwardly as the'case may be. Such operation oscillates or rocks thehangers about the pivots formed by the bolts 9 and results in theadjustment of the cutting edge of the ledger bar toward or away from thepath of the cutter blades C.

For this purpose the studs I3 carrying the cams I! have their outer endsreduced and squared off at H and lock nuts 15 are provided on the studson outer surfaces of the frame members. By the use of a wrench,therefore, the studs may be turned to move the cams as required and theadjustrnent secured by tightening the lock nuts.

The ledger bar as it is adjusted moves in a vertical plane and in a foreand aft direction due to its overhead pivots and as. a result the planetherefore fully illustrated and described my invention, what I claim tobe new and desire to protect by Letters Patent is:

1. In a lawnmower, a frame, a rotary cutter journaled in the frame andhaving blades adapted to travel a circular path, a unitary ledger plateof arcuate formation in-cross section for coaction with the rotarycutter, said ledger plate possessing suflicient rigidity to act as abrace be-.

tween the sides of the frame, and means for adjustably supporting theunitary ledger plate, said means engageable with the ledger plate onlyat the ends thereof to increase grass clearance between the frameportions, the adjustable supporting means for the, ledger plate extendinthrough. the frame and being operable at the outer sides of the frame.

2. In a'lawn mower, a frame, a rotary cutter journaled on a transverseaxis in the frame, a unitary ledger plate for cooperative cutting actionwith the rotary cutter, said unitary ledger plate being substantiallyparallel with the ground line during normal operation of the mower,hanger members substantially perpendicular to the ledger plate andhaving pivotal connections between their upper and lower ends with theframe and swingably supporting the ledger plate at their lower ends foradjustment toward and away from the cutter, adjusting means associatedwith the upper ends of the hanger members extending through the frameand operable at the outer sides of the frame for swinging the hangermem-- bers and ledger plate in the frame, and said pivotal connectionsand adjusting means being located substantially along radial linesextending downwardly from the cutter axis.

3. In a lawn mower, a frame, a rotary cutter mounted in the frame andhaving blades adapted to turn about the cutter axis, a unitary ledgerplate substantially parallel with the ground line during normaloperation of the mower, hanger members substantially perpendicular tothe ledger plate pivotally connected to the frame between the upper andlower ends thereof and supporting the ledger plate at their lower endsfor swinging movements toward and away from the path of the cutterblades, means for engaging the upper ends of the hanger members forswinging the same about the axes of their pivotal connections with theframe, and both the said adlusting means and the pivotal connectionsbeing located between the axis of the cutter and the path of the cutterblades and extending through the frame to the exterior thereof foroperation at the outer sides of the frame.

4. In a lawn mower wherein a frame carries a rotating reel cutter with aledger platecooperating therewith, such ledger plate being of one-piececonstruction and supported from the frame by supports located whollyabove the plate faces and secured to the upperplate face in a manner tolocate the supports symmetrically to the width of the ledger plate tothereby place the lower face of the ledger plate as the bottom of theplate assembly, whereby such lower face is spaced from the groundsurface for grass clearance purposes, said'ledger platebeing arcuate incross section and said ledger plate and its supports providing asubstantially rigid structure between the sides of the frame whereby theledger plate curvature and the supports therefor permit adjustment ofthe plate without affecting the grass clearance space dimensions.

ADOLPH RUNNING.

